What feature allows conditional changes to cell appearance in Excel?

Conditional Formatting is the feature in Excel that allows for dynamic changes to a cell's appearance based on the values contained within that cell or other cells. This powerful tool enables users to apply different formatting options such as font color, background color, border styles, and more, based on predefined rules or conditions.

For example, you can set a rule that highlights all cells with a value greater than a certain number in red or turns them green if they meet a particular criterion. This visual representation helps in quickly identifying trends, patterns, or critical values within a dataset, making analysis more intuitive and effective.

The other features listed, such as Data Validation, Cell Protection, and Formula Auditing, serve different purposes. Data Validation restricts what can be entered into a cell, Cell Protection secures cells from editing, and Formula Auditing is used for tracking and verifying formula errors. Each has its role, but none provide the same aesthetic and conditional response capabilities that Conditional Formatting does.